Engineering Standards Research Articles

Regolith-Rich PEEK Composite Bricks: Steps Towards Space-Ready Lunar Construction Materials

This study introduces a novel composite construction material composed of lunar regolith combined with PEEK in dry powder form. The work demonstrates significant advantages over alternative methods, primarily by reducing production power consumption and simplifying the manufacturing process. Building on previous research that explored binder optimization through process simplification and targeting predefined shapes, this work delves deeper into a comparative analysis of high-performance thermoplastics. Among the various options, PEEK demonstrates the most favorable properties. The study investigates key processing parameters and evaluates the effects of vacuum processing and temperature testing on mechanical properties. The research also evaluates the effects of vacuum processing and temperature testing to assess the material’s performance under lunar conditions. Comparative analysis is performed with standard performance of various reinforced and unreinforced concretes and with standard requirements for construction bricks as per ASTM standards. This shows that the composite, with an organic binder content as low as 5 wt%, has great potential. Notably, the improvements achieved through vacuum curing ensure compliance with lunar environmental conditions and alignment with most Earth-based engineering standards. Samples compacted at 7.50 MPa with 10 wt% binder, and tested at room temperature, achieve a compression strength of 16.3 MPa, exceeding that of industrial floor bricks and matching that of building bricks used on Earth. Bending strength (7.4 MPa) aligns with steel fiber-reinforced and high-strength concretes. Vacuum curing further enhances these properties, with an observed increase of +66% in bending strength and +33% in compression strength.

Wear Analysis of Polymer Brake Pads Using Non-Destructive Testing Techniques

The research investigates the wear characteristics of polymer and composite brake pads like aramid fibers, potassium titanate, and phenol formaldehyde resin, which are crucial for vehicle safety and performance. Non destructive testing (NDT) techniques, including spectroscopic methods and particle size distribution analysis, are employed to assess brake pad materials' durability without compromising component integrity. The study highlights the role of NDT in understanding friction material behavior, as well as recent developments and challenges in NDT methods like dynamometer noise measurement. It underscores the environmental benefits of integrating natural fibers in brake pads and the advancements in NDT technologies, such as ultrasonic scanning and laser-based techniques, which enhance brake system safety and efficiency. The research emphasizes the need for continuous innovation and adherence to quality standards in automotive engineering to develop more advanced and sustainable braking systems. Such investigations not only enhance our understanding of the behavior of materials under various types of stresses but also pave the way for further improvements in the performance and sustainability of brake pads.

Capital budgeting for electrical engineering projects: A practical methodology

The paper presents the capital budgeting process and identifies key elements in the process. A standardized approach in capital budgeting by application of information technology resources for both proposal submission and documentation becomes key to success in handling large volumes. An electrical engineering distribution system design project involves the application of engineering codes and standards to stay compliant and provide safe design and construction. A model starting with proposals acceptance to evaluation and approval of capital projects was presented. The proposal stage was decoded further into assessments of the existing electrical infrastructure based on aging and engineering standards. Upon review of the standards, the proposals were accepted for evaluation and approval. For business professionals, there is a gap when working in an electrical engineering construction industry when it comes to knowing applicable engineering standards and their application. This research filled that gap by enlisting the intent of the standards review process. Although the focus was on understanding a holistic approach to electrical engineering projects, a detailed analysis of specific tasks may be designed based on the model presented in this paper. Additionally, the transmission side of projects will have a similar application of capital budgeting.

Synergy effects of phosphogypsum on the hydration mechanism and mechanical properties of alkali-activated slag in polysilicon sludge solidification

Polysilicon sludge (PSS), due to its high organic impurity content, poses significant challenges in solidification using traditional cementitious materials, failing to meet engineering standards. As such, alternative solidification methods are urgently needed to enhance PSS resource utilization. This study explores the use of phosphogypsum (PG) to improve the alkali activation process in the solidification of PSS with slag. Given that calcium sulfate in PG promotes alkali activation, this research investigates the synergistic effects of PG, PSS, and slag as precursors in developing an eco-friendly, resource-efficient solidification approach. Comprehensive characterization techniques, including X-ray diffraction, thermogravimetric analysis, mercury intrusion porosimetry, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, and solid-state magic-angle spinning nuclear magnetic resonance were employed to assess the influence of PG and PSS dosages on the hydration behavior, mechanical properties, and microstructure of the alkali-activated system. Results demonstrated that the addition of 5 wt% PG significantly improved slag dissolution promoted the formation of hydration products such as hydrated calcium aluminate, reduced sample porosity, and refined the pore size distribution. These effects mitigated the inhibitory impact of PSS on the alkali activation process. However, higher dosages of PG and PSS reduced the system's pH, which in turn hindered early slag solubility and compromised the early strength of the solidified product. In addition, the ternary alkali-activated system developed in this study effectively immobilized heavy metals present in both PSS and PG, thus enabling the synergistic utilization of these waste materials while enhancing environmental compatibility. The findings provide valuable theoretical insights into the use of alkali-activated systems for solidifying waste materials and promote the development of resource-efficient, sustainable waste management strategies. This study paves the way for future research into optimizing the composition of PG, PSS, and slag mixtures to further enhance mechanical performance, long-term stability, and environmental safety.

Predicting bond strength of corroded reinforced concrete after high-temperature exposure: A stacking model and feature selection

The bond strength between concrete and steel reinforcement bars is crucial for determining the ultimate load-carrying capacity and serviceability of reinforced concrete (RC) structures. However, rebar corrosion and exposure to high temperatures significantly affect this bond strength. Regrettably, research on the combined effect of these two factors on bond strength is scarce, and there is a lack of a unified, precise, and efficient predictive model. This research developed a stacking model to forecast bond strength under the combined impact of high temperature and corrosion. The initial layer of the model comprises SVR, KNN, MLP, RF, GBDT, and XGBoost as base learners, with the second layer being the linear regression model. The analysis led to the following conclusions: In a comparative study, the stacked model demonstrated superior performance compared to the six base learner models (SVR, KNN, MLP, RF, GBDT, and XGBoost). Among all combinations, Stacking Model Three showed the most robust predictive performance, achieving an R² value of 0.9439, an MAE of 0.8553, an MSE of 2.2721, and an RMSE of 1.5073. Stacking Model Three surpassed XGBoost, the most effective base learner, showing improvements of 1.78 % in R², 20.69 % in MAE, 22.66 % in MSE, and 12.05 % in RMSE. The machine learning model’s enhanced reliability was further confirmed by comparison with existing models. Stacking Model Three outshone the Australian Standard model with improvements of 639.04 % in MAE, 2568.77 % in MSE, and 416.61 % in RMSE. Similarly, XGBoost, the top base learner, exceeded the Australian Standard model with gains of 486.09 % in MAE, 1964.39 % in MSE, and 354.36 % in RMSE. The outcomes of the SHapley Additive exPlanations (SHAP) affirm the interpretability and physical validity of the stacking model employed. The SHAP analysis indicates that the corrosion level of steel bars (CL) and temperature (T) are the critical factors influencing bond strength. This research underscores the practical value of SHAP feature importance in feature selection by comparing the predictive performance of stacked models with various input feature combinations, thus confirming that feature selection significantly impacts the model’s predictive accuracy. In optimizing traditional civil engineering standards and empirical formulas, the feature selection results of machine learning can be referenced.

Additive manufacturing in construction using unmanned aerial vehicle: Design, implementation, and material properties

Currently, 3D printing concrete method is mostly being developed based on on-site construction. This study addresses the inherent limitations of conventional on-site 3D printing in construction, particularly the challenges posed by constrained working environments and equipment restrictions. To overcome these obstacles, the research introduces a novel architectural additive manufacturing process utilizing unmanned aerial vehicle (UAV), enabling off-site 3D printing of complex geometric structures. The primary aim of the study is to develop UAV-based equipment capable of autonomous 3D printing and real-time structural assessment, thereby enhancing the flexibility and adaptability of construction technologies. The methodology involves the design, development, and integration of a UAV-enabled additive manufacturing system, incorporating specialized components, including a cementitious material optimized for aerial deposition. Experimental testing focused on evaluating printability, structural integrity, and material performance, with compressive strength tests yielding values up to 39 MPa at 60 days, meeting general engineering standards. The findings of this study confirm the feasibility of combining UAV technology with 3D printing to improve operational flexibility and accessibility, particularly in remote or difficult-to-reach locations where conventional construction methods are impractical. This research makes a significant contribution by addressing the limitations of traditional 3D printing techniques and presenting a new avenue for construction automation. The innovative UAV-based system offers potential applications in diverse fields, including disaster response, space exploration, and infrastructure development in remote or hazardous environments. As such, this study provides a foundational basis for future advancements in UAV-driven construction technologies and opens up new possibilities for autonomous construction solutions.

Research on the Identification of Rock Mass Structural Planes and Extraction of Dominant Orientations Based on 3D Point Cloud

The different spatial distribution forms of rock mass structural planes create weak zones in the rock mass, which is also a key factor in controlling rock mass stability. Accurately and efficiently identifying rock mass structural planes and obtaining their dominant orientations is critical for rock mass engineering design and construction. Traditional surveying methods for high and steep rock mass structural planes pose high safety risks, offer limited data, and make comprehensive statistical analysis difficult. This paper utilizes complex rock mass surface 3D point cloud data obtained through 3D laser scanning technology and uses the Hough space transform method to calculate the normal vectors of the 3D point cloud. Based on the difference in normal vectors and surface variation, region growing segmentation is applied to identify and extract rock mass structural planes. Additionally, the fast search and density peak clustering method (CFSFDP) is used for clustering analysis of the rock mass structural planes to obtain dominant orientations. This method was applied to a highway’s high and steep rock slope, successfully identifying 281 structural planes and two sets of dominant structural planes. The orientation of the dominant structural planes identified through RocScience Dips 7.0 analysis showed a deviation of no more than ±3°, complying with engineering standards. The research results offer a feasible solution for the identification of high and steep rock mass structural planes and the extraction of the orientation of dominant structural planes.

Effect of steam curing regime on the mechanical properties, drying shrinkage, and microstructure of mortar in high-altitude areas with low air pressure

Low air pressure in plateau regions impacts the microstructure and macroscopic properties of cement-based materials by altering water transport. However, the efficiency of steam curing, a frequently-used curing approach, under these conditions has been inadequately studied. This work compares the effects of steam curing on the mechanical properties, drying shrinkage, and microstructure of cement-based materials at low air pressure. Results show that low air pressure decreases the compressive strength and increases the drying shrinkage of steam-cured mortar due to reduced hydration and increased total pore volume. Optimally, a steam curing temperature of 40°C to 60°C minimizes thermal damage, and a pre-curing time of 3 hours yields the best mechanical properties and drying shrinkage. Additionally, a field case confirms the effectiveness of the proposed steam curing regime; the demolding strength of precast beams meets engineering standards, and drying shrinkage fluctuates significantly with daily temperature changes. Notably, a 25.30 % difference in 90-day drying shrinkage between steam-cured and non-steam-cured specimens underscores the necessity of steam curing in high-altitude areas. These findings are crucial for optimizing steam curing practices in low-pressure environments.

Inversion Model for Permeability Coefficient Based on Random Forest–Secretary Bird Optimization Algorithm: Case Study of Lower Reservoir of C-Pumped Storage Power Station

The geological complexity of the karst regions presents significant challenges, with the permeability coefficient being a critical parameter for accurately analyzing seepage behavior in hydraulic engineering projects. To overcome the limitations of traditional inversion methods, which often exhibit low computational efficiency, poor accuracy, and instability, this study utilizes a finite-element forward model and orthogonal experimental design to establish a sample set for permeability-coefficient inversion. A surrogate model for seepage calculation based on the Random Forest (RF) algorithm is subsequently developed. Furthermore, the Secretary Bird Optimization Algorithm (SBOA) is incorporated to propose an intelligent RF–SBOA inversion method for permeability-coefficient estimation, which is validated through a case study of the C-pumped storage power station. The results demonstrate that the RF model’s predictions for water levels at four boreholes closely align with the measured data, outperforming models such as CART, BP, and SVR. The SBOA effectively identifies the optimal geological permeability coefficient, with the borehole water-level inversion achieving a maximum relative error of only 0.128%, which meets the accuracy requirements for engineering applications. Additionally, the computed distribution of the natural seepage field is consistent with the typical distribution patterns observed in mountain seepage systems. During the normal water-storage phase, both the calculated seepage flow and gradient comply with engineering standards, while the seepage-field distribution aligns with empirical observations. This inversion model provides a rapid and accurate method for estimating the permeability coefficient of strata in the project area, with potential applicability to permeability inversion in other engineering geology contexts, thus demonstrating considerable practical value for engineering applications.

Cyber Resilience Limitations in Space Systems Design Process: Insights from Space Designers

Space technology is integral to modern critical systems, including navigation, communication, weather, financial services, and defence. Despite its significance, space infrastructure faces unique cyber resilience challenges exacerbated by the size, isolation, cost, persistence of legacy systems, and lack of comprehensive cyber resilience engineering standards. This paper examines the engineering challenges associated with incorporating cyber resilience into space design, drawing on insights and experiences from industry experts. Through qualitative interviews with engineers, cybersecurity specialists, project managers, and testers, we identified key themes in engineering methodologies, cybersecurity awareness, and the challenges of integrating cyber resilience into space projects. Participants emphasised the importance of incorporating cybersecurity considerations from the earliest stages of design, advocating for principles such as zero-trust architecture and security by design. Our findings reveal that experts favour Model-Based Systems Engineering (MBSE) and Agile methodologies, highlighting their synergy in developing flexible and resilient systems. The study also underscores the tension between principles-based standards, which offer flexibility but can lead to inconsistent implementation, and compliance-based approaches, which provide clear measures but may struggle to adapt to evolving threats. Additionally, the research recognises significant barriers to achieving cyber resilience, including insider threats, the complexity of testing and validation, and budget constraints. Effective stakeholder engagement and innovative funding models are crucial for fostering a culture of cybersecurity awareness and investment in necessary technologies. This study highlights the need for a comprehensive cyber resilience framework that integrates diverse engineering methodologies and proactive security measures, ensuring the resilience of space infrastructure against emerging cyber threats.

Quality inspection method of BIM model for power grid engineering based on knowledge graph

With the continuous updating of national specifications and industry standards, the traditional manual compliance review method is difficult to meet the needs of the development of the construction industry. This study aims to improve the quality review method of BIM models by using knowledge graph technology. The BIM model of power grid engineering is selected as the research object, and a BIM model inspection system based on knowledge graph is developed to verify whether it complies with the relevant specifications and standards of power grid engineering. By taking the BIM model of an electrical engineering project as a case, an inspection report was generated, and the results verified the feasibility and practicality of this method. This technology provides a new direction for the deep integration of architectural design and information technology.

A Review of Agrivoltaic Systems: Addressing Challenges and Enhancing Sustainability

Agrivoltaics is a relatively new term used originally for integrating photovoltaic (PV) systems into the agricultural landscape and expanded to applications such as animal farms, greenhouses, and recreational parks. The dual use of land offers multiple solutions for the renewable energy sector worldwide, provided it can be implemented without negatively impacting agricultural production. However, agrivoltaics represent a relatively new technology, facing challenges including economic viability, vulnerability to wind loads, and interference with growing crops. This paper reviews the recent research on integrating agrivoltaics with farming applications, focusing on challenges, wind impact on agrivoltaics, and economic solutions. The effect of agrivoltaics on temperature control of the lands is a critical factor in managing (1) water and the soil of the land, (2) animal comfort, and (3) greenhouse productivity, positively or negatively. In this review, a contradiction between the different versions of the American Society of Civil Engineers (ASCE) standards and the wind tunnel results is shown. Important factors affecting the wind load, such as damping and mass increase, optimum stow position, and aerodynamic edge modification, are highlighted with emphasis on the significant knowledge gap in the wind load mitigation methods.

Stabilization effect of nano-SiO2@iron-phosphorus on ferrallisols, calcareous soil and organic soil heavily polluted by heavy metals: A fast reaction curing stabilization process

The remediation of soil pollution by heavy metals (HMs) presents a significant challenge in environmental restoration. Stabilization remediation technology has proven effective in treating HMs contaminated soil. However, its development is constrained by drawbacks such as slow reaction kinetics and low adsorption capacity. This research synthesized a nano-SiO2@iron‑phosphorus (FPOH) material by SiO32− encapsulating the iron-phosphate precipitate obtained from Fe ion and phosphate. In addition, this research applied this material to ferrallisols, calcareous soils and organic soils with three different levels of high pollution by Cd, Pb, Cu and Zn. The experimental results indicate that all experimental soils stabilized rapidly within 1 day and met the requirements of remediation engineering standards (ChinaMEE HJ 1282-2023). Analysis of the possible mechanisms suggests that the FPOH material effectively fills voids with phosphate mineral formation, preventing the secondary release of HMs. During the stabilization process, FPOH involves the adsorption of free ions and small organic molecules in the soil, which does not affect its high reactivity. The development and utilization of FPOH offer valuable insights for soil stabilization remediation.

Supporting driver performance in closely spaced tunnel-interchange structure: Traffic control devices and effects on driving behavior

Objectives With the rapid development of expressways in the mountainous regions of southwestern China, closely spaced tunnel-interchange structures have inevitably emerged due to topographical constraints and environmental limitations. Given the unfavorable road geometry and rapid cross-section transitions, drivers face significant safety concerns. This study aims to investigate drivers’ safety performance at closely spaced tunnel-interchange sections and determine how safety risks can be mitigated through improved traffic control devices design. Methods Thirty-nine participants conducted an experimental study in a fixed-base simulator. The test scenario was modeled on the Xingyan Freeway-S3801 and accurately reproduced in the simulator. For each safety performance metric, the driving simulator experiments yielded a dataset with 780 observations. To address the idiosyncratic variation due to individual driver differences, a series of linear mixed effects models (LMM) were developed to analyze drivers’ behavior responses. Results In closely spaced tunnel-interchange sections, a general impairment of both longitudinal and lateral performance was observed. This study identified potential critical impact variables in traffic control device systems. According to the LMM results: (a) Removing the 0.5 km interchange ramp exit advance guide sign located in the tunnel exit area reduces dangerous behavior in the corresponding impact area. (b) Replacing the 0.5 km interchange ramp exit advance guide sign with arrow pavement markers as an information source supports improved driver performance, promoting driver safety. (c) Adding tunnel exit distance signs within tunnels is recommended to enhance situation awareness for drivers. Conclusions This study addresses the scientific issues related to traffic control devices setup for closely spaced tunnel-interchange sections, focusing on identifying potential critical impact variables. The findings provide guidance on the design of traffic control devices for such sections and support revisions to national engineering standards.

RESEARCH OF THE COMBUSTION PARAMETERS OF GASOLINE WITH ADDITIONAL HYDROGEN IN A SPARK-IGNITION ENGINE IN EXTERNAL SPEED CHARACTERISTIC MODES

The directions of development and improvement of road transport around the world are inextricably linked to the desire to reduce the use of cars “on traditional fuels” due to limited oil and environmental safety of mankind. Since the modes of external speed characteristic are the most typical for the operation of cars in cities, the study of environmental performance of engines in these modes is an urgent task. Therefore, finding ways to reduce carbon dioxide emissions from automobile engines at high-speed modes is an urgent task. The rapid growth in the number of cars with internal combustion engines and the inevitable decline in world oil reserves necessitate the development and implementation of energy-saving technologies and the use of alternative fuels. Research aimed at finding ways to improve the fuel efficiency and environmental performance of automotive engines is relevant. One of the promising areas is the influence on the combustion process in gasoline engines by using additives of alternative fuels, which include hydrogen. The presented study of the parameters of combustion of gasoline with hydrogen additive in a spark ignition engine at external speed characteristics is a comprehensive analysis of the combustion process of a gasoline-hydrogen mixture and determination of its effect on the concentration of carbon dioxide in exhaust gases by developing a mathematical model that takes into account the composition of the mixture components and features of the combustion process, allows for sufficiently accurate calculation of the operating process of an engine with hydrogen additive at ψ ≤ 10%, its identification by the results of experiments. In the course of the study, dependencies were developed to determine the combustion parameters of the Wiebe model, taking into account the addition of hydrogen to gasoline in the modes of external speed characteristics, and the effect of hydrogen addition on the concentration of CO2 in exhaust gases was analyzed. It is shown that with an increase in the hydrogen additive to 10% by mass fraction to gasoline, there is a decrease in CO2 emissions to almost 30% in the external speed characteristic modes, which corresponds to modern environmental standards for gasoline internal combustion engines.

Assuring fire safety in nuclear plants with international standards

This paper presents the evolution and benefits of international standards for fire safety engineering11Fire safety engineering and performance-based fire safety are both widely used, and both represent an engineering process to determine performance of a fire protection plan based on the results of fire calculations. developed at the International Organization of Standardization (ISO). The history of fire safety in nuclear power plants along with the need for fire safety regulation is discussed to lay the foundation for the standards development work. The evolution of fire safety regulation from prescriptive to performance-based is also presented as the background for the research.Extensive research of the issues that arise for performance-based fire safety regulation, specifically for computer models for fire safety calculations, which included international benchmark exercises formed the basis to identify the need for developing international standards for fire safety engineering. The research focused both on the verification and validation (V&V) of computer fire models and determining their predictive capability. The paper for the first time takes new scientific and engineering data from benchmark exercises to assess the suitability and applicability of computer fire models for application in nuclear power plants. The paper reports on the findings of the benchmark exercises and their use in formulating new requirements in ISO international standards on verification and validation of fire calculation methods and the fire safety engineering process through a consensus process of international experts.Discussion of the foundational research at the ISO fire safety engineering committee (ISO TC 92 SC 4) led to a consensus to revise two international standards. One specifying the principles and general requirements for fire safety engineering, and another on the verification and validation procedures for fire calculation methods. The development and content of these two international standards are discussed in this paper. An international technical report was subsequently developed at the ISO committee for conformity assessment (CASCO) to provide guidance for the certification of the fire safety engineering process, and specific parts of it, namely the V&V of fire calculation methods.It is concluded that the fire safety engineering international standards presented in this paper can support rigorous performance-based fire safety regulation for nuclear power plants. These ISO international standards will be particularly useful to nations that have not yet developed the regulatory infrastructure for nuclear power regulation. The international standards are also available to those that would like to transition to the use of international standards and an ISO standards-based certification scheme. Regulations based on these international standards will provide citizens with confidence in nuclear power as a viable option to address climate change.

Trip Attraction Rate Estimation Using Open Data Sources for Smart Transportation Planning

Trip Attraction Rate (TAR) serves as a load factor utilized in aggregate transportation modeling. Conventional estimation consumes a lot of time and manpower for field surveys. Meanwhile, open data sources, such as Google Maps, offer an alternative approach to conducting a survey. The popular times feature from Google Maps can estimate coffee shop TAR in the city of Bandung. This study focuses on coffee shops in Bandung City. Data was collected using web scraping techniques on Google Maps and produced a sample size of 377 data points after the validity and reliability processes. Subsequently, multiple linear regression was employed to estimate TAR. The findings reveal that variables like building area and distance to public transportation hubs influence TAR simultaneously. Moreover, our approach could also distinguish TAR between weekdays (0.13 people/m2/hour) and weekends (0.14 people/m2/hour) in Bandung City. This result challenges the usage of Institute of Transportation Engineers (ITE) standards, which is often due to limitations of time and workforce in conducting surveys for TAR estimation. The difference in values indicates the need to estimate specific TAR for each city in Indonesia rather than relying on ITE values, and the proposed approach to using open data sources will shorten the estimation process.

Analysis on the Establishment of Standardized Management System for the Operation of Sluice Engineering

Baiyanghe Xiaocaohu Hub is an important water diversion hub project for industrial and agricultural water supply in Toksun County, Turpan City. After the project was reinforced in 2018, it plays an important role in local social stability and economic development. In recent years, in order to implement the new development concept, promote high-quality development, and improve the scientific level of water gate management, in accordance with the requirements of higher-level work deployment, the main responsibility of management has been implemented, and a comprehensive transformation has been carried out from five aspects of Xiaocaohu Water Conservancy Hub to improve the current situation of the project, standardize management behavior, and enhance management capabilities. This article summarizes the experience of standardization implementation, explores the formation of replicable and promotable management experience, and provides reference for promoting engineering standardization management work from point to area.

Utilization of waste materials for soil stabilization: A comprehensive review

Soil stabilization, is a crucial aspect of civil engineering, entails the modification of soil properties to meet specific engineering standards. This is conventionally achieved through compaction and the incorporation of stabilizing agents or admixtures. Lime and cement have been predominant choices for soil stabilization, demonstrating effectiveness in altering soil properties. However, recent research has unveiled a notable shift towards the utilization of waste materials, such as fly ash and rice husk ash, for soil stabilization purposes. These waste materials, when used alone or in conjunction with lime or cement, have shown promise in achieving the desired engineering outcomes. The literature review conducted for this purpose delves into the existing body of knowledge on the utilization of waste materials in soil stabilization. Emphasizing their potential benefits, the review explores the effectiveness of these materials in altering soil properties and meeting engineering specifications. By investigating alternative stabilizing agents derived from waste materials, this research contributes to a sustainable approach in soil engineering practices. The findings presented in this paper shed light on the potential of waste materials for soil stabilization, offering a viable solution for waste disposal while addressing environmental concerns associated with traditional stabilizers.

Identifying the effect of low-cycle fatigue of reinforced concrete structures on the properties of the reducing coefficient under the action of a seismic type load

The object of consideration is seismic design, and the subject of the study is the determination of the reduction coefficient. One of the important problems of earthquake-resistant design is to determine the effect of low-cycle fatigue of reinforced concrete on the reduction coefficient and determine its optimal value. This problem is not disclosed and is not specifically taken into account in the standards for earthquake engineering when determining the maximum bearing capacity of types of structures due to the lack of study of the issue. To solve the problem, a series of experimental studies were carried out on low-cycle fatigue of reinforced concrete bending elements and frame units. The range of results of the reduction coefficient values and the degree of influence of monocyclic fatigue on the properties of the reduction coefficient are obtained. A feature and characteristic of the results obtained is that the reduction coefficient Rμ depends on the nature of the hysteresis deformation pattern and the plastic life of structural elements estimated by the plasticity coefficient μ, which is significantly influenced by low-cycle fatigue manifested at peak accelerations of strong seismic impacts. The above test algorithm, the feature and characteristics of the results obtained made it possible to solve the problem under study. The results obtained are accepted for practical use in the action of seismic loads: on the calculation of strength taking into account new low-cycle coefficients, reduction coefficients for determining the spectra of design reactions and seismic loads, taking into account energy absorption. New reduction coefficients are proposed for determining the spectra of calculated reactions and seismic loads